Added a project info system for devlog entries. Each devlog tag can now have associated metadata defined in src/data/projects.ts including a description, source repo, live URL, and additional links. A new ProjectInfo component displays this information on devlog pages, replacing the hardcoded spacetraders links that were there before.

Extended the remark-post-links plugin to support a link: prefix for external markdown links. This allows posts to reference external URLs with a shorthand syntax like [text](link:slug) where the slug maps to a predefined URL.

Also added post filtering to the blog index and backfilled many devlog entries for the spacetraders-v1 and bags projects.